People in Guatemala carry machetes. You won't see this so much in the city (unless maybe machete juggling on 6th ave?), but in rural areas it's pretty much ubiquitous. And no, you're not in danger -- probably. Sure, machetes are weapon-like, sharp, and can make their wielder look pretty grisly. But the fact is that in rural Guatemala the most widely applicable, purely necessary general tool for most types of work is the machete.
Kids carry machetes, men carry machetes, groups of people carry machetes. Most laborers actually carry metal files, too, to keep their machetes sharp and serviceable. That's mainly because the type of work that most of these people are engaged in requires a machete. What type of work is that? Cutting grass, weeding, tending fields, etc.
People even bring their machetes into buses, pickups or other forms of colectivo transport.
So, are you in danger with so many people carrying machetes around? Generally speaking, no. Dangerous people are dangerous, but machetes are just a way of life in rural Guatemala. Think of them like briefcases in the west, if that helps.